CVE-2026-40198: high-severity vulnerability in STIGTSP Net::CIDR::Lite
Net::CIDR::Lite versions before 0.23 for Perl does not validate IPv6 group count, which may allow IP ACL bypass
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.3%
Net::CIDR::Lite versions before 0.23 for Perl does not validate IPv6 group count, which may allow IP ACL bypass.
_pack_ipv6() does not check that uncompressed IPv6 addresses (without ::) have exactly 8 hex groups. Inputs like "abcd", "1:2:3", or "1:2:3:4:5:6:7" are accepted and produce packed values of wrong length (3, 7, or 15 bytes instead of 17).
The packed values are used internally for mask and comparison operations. find() and bin_find() use Perl string comparison (lt/gt) on these values, and comparing strings of different lengths gives wrong results. This can cause find() to incorrectly report an address as inside or outside a range.
Example:
my $cidr = Net::CIDR::Lite->new("::/8");
$cidr->find("1:2:3"); # invalid input, incorrectly returns true
This is the same class of input validation issue as CVE-2021-47154 (IPv4 leading zeros) previously fixed in this module.
See also CVE-2026-40199, a related issue in the same function affecting IPv4 mapped IPv6 addresses.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Affected products
STIGTSP · Net::CIDR::LiteRelated CVEs — STIGTSP Net::CIDR::Lite
In the same product, most dangerous first.
CVE-2026-40199MEDIUMNet::CIDR::Lite versions before 0.23 for Perl mishandles IPv4 mapped IPv6 addresses, which may allow IP ACL bypassEPSS 0.3%CVE-2026-45190MEDIUMNet::CIDR::Lite versions before 0.24 for Perl does not properly validate IP address and CIDR mask inputs, which may allow IP ACL bypassEPSS 0.3%CVE-2026-45191MEDIUMNet::CIDR::Lite versions before 0.24 for Perl does not properly consider extraneous zero characters in CIDR mask values, which may allow IP ACL bypassEPSS 0.3%